As the sun comes up, the sun and the "sky" shine into homes, offices and other buildings or structures with windows. That does two important things:
1. It increases the heat in the buildings due to solar energy. That heat input is in the form of direct sunshine, reflected "sky" radiation, and solar radiation reflected through windows from all non-black objects around the buildings.
2. The rising sun increases the amount of natural light, so it decreases the need for artificial illumination for reading, working and so on.
On warm or hot days the air conditioning comes on early. Even on many cool or cold days of the year, the combined effects of many air conditioning systems coming on in a given city or area overloads electric power generators, blows fuses, overloads transformers and causes blackouts, damage to electrical equipment, and so on. Often the electric power company can not produce enough electricity so it must reduce the voltage (power delivered) by 3% to 5% or more.
Those problems are unnecessary, in many instances, and energy is wasted for three reasons. 1. Energy is wasted in producing light (and heat) when natural outside light increases the light coming in through windows. 2. Energy is wasted for running air conditioning systems to pump the heat produced by the lamps to the outside. 3. The light that is shining on the occupants is converted to heat which warms their skin surfaces, making them feel too warm, so they turn the thermostat down to overcome that overheated feeling.
Someone could go through offices, homes, etc. turning off some of the lights to avoid over-lighting, and consequent overheating. But, that would require an engineer or maintenance man, at great cost. He would not be as reliable as simple automatic equipment actuated to do the job as taught in the present invention. This invention will cut out certain lamps, or otherwise lower the level of illumination in response to the air conditioning equipment coming on. In another form of the invention, artificial illumination may be decreased in response to air conditioning plus sunshine, sky radiation and reflected sunlight. Or, artificial illumination may be decreased during certain hours of the day or night while the air conditioner is on.
In view of the world-wide energy shortage, and high cost of energy, many persons would be willing to have the lighting level reduced somewhat below so-called "normal" levels during periods of peak power need for air conditioning. Some would be willing to avoid waste of energy that produces excess heat through lamps, plus wasting extra energy to pump the excess heat out, plus waste of energy to cool the skin that is over-warmed due to light from the lamp bulbs. Some would agree to having some of the lights turned out rather than overload generators, fuses, transformers, and such, and rather than endure blackouts, damaged equipment due to overloading, and so on.
So, no matter what the reason, many persons would agree that some lamps should be turned off, and the level of illumination reduced when air conditioning equipment comes on. This invention provides such feature, simply and automatically, without fail and without extra costs for a janitor, maintenance man, engineer, clean-up crew, or other.